The invention is directed to an apparatus for the production of water from air. In particular, the invention is directed to an apparatus for the production of drinking water.
There are many known systems for removing water from the air. These tend to be devices which are commonly called xe2x80x9cdehumidifiersxe2x80x9d. For example, New Zealand Patent No. 270431 to EBAC Limited, entitled xe2x80x9cdehumidifiersxe2x80x9d is a case in point. This New Zealand patent discloses a device for extracting moisture from the air in a building. The invention to which this New Zealand patent is directed is described as being a dehumidifier in which a refrigerant is circulated by a compressor through an evaporator, which becomes cold, and a condenser, which becomes warm, and air is passed over the evaporator so that any moisture in the air condenses on the evaporator, following which the air passes over the condenser to be warmed before leaving the dehumidifier. If the water that collects on the evaporator freezes, the dehumidifier periodically enters a defrost mode which allows the ice to melt. Therefore, creation of ice on the evaporator is a problem of operating a dehumidifier of this type. Such dehumidifiers are not directed to the production of drinking water but are rather directed to the removal of moisture from the air.
Devices which are directed specifically to the production of the water are also known. One device called the xe2x80x9cWATERMAKERxe2x80x9d is manufactured by Electric and Gas Technology, Inc. of Dallas, Tex., U.S.A. This device operates by drawing room air into the device through a disposable air filter. This filtered air then passes through cooling coils that are made of a refrigerator alloy coated with polyurethane. These coils are kept at a temperature of approximately 39xc2x0 F. Some of the moisture in the filtered air will condense on these coils resulting in droplets of distilled water. The water droplets run down the coils and collect in a funnel that feeds the water into a holding tank. This tank is held inside a cooled box which has its own cooling system and is fully insulated. There are a number of difficulties with this technology. The apparatus requires humid air in the surrounding atmosphere. Once the air has been dehumidified, the apparatus stops. In addition, once ice forms on the coils, the melting of this ice is achieved by using hot gas from the condenser in a manner which is inefficient.
It is an object of the invention to provide an apparatus which meets some of the difficulties of prior art devices or at least to provide the public with a useful choice.
The invention in the first aspect is an apparatus for the production of water from air wherein the apparatus includes:
(a) an air intake device adapted to move air into the apparatus;
(b) an evaporator adapted to freeze the water contained in the air issuing from the air intake device; and
(c) defrosting means adapted to defrost the water frozen by the evaporator;
and wherein the volume of air passing over the frosting surface of the evaporator is controlled by either the air intake device or the evaporator.
Preferably the air intake device is adapted to move a variable volume of air over the evaporator and the evaporator is of constant frosting area.
Preferably the air intake device is adapted to move a constant volume of air over the evaporator and the evaporator has a variable frosting area.
Preferably, the apparatus further includes a reservoir to collect the water created from defrosting the evaporator.
Preferably, the apparatus further comprises an air filter situated to filter the air moving into apparatus.
Preferably, the filter is a washable or a disposable filter.
Preferably, the filter is 200 micron washable filter.
Preferably, the defrosting means includes a defrost sensor to detect when a predetermined amount of ice or frost has formed in the evaporator.
Preferably, the air intake device is a fan adapted to draw air into the apparatus through the evaporator.
Preferably, the air intake device is a blower adapted to force air into the apparatus.
Preferably, the evaporator may include one or more helically corrugated conduits as described and claimed in International Patent Application Number PCT/NZ93/00087.
In an alternative form, the evaporator may include a plurality of interconnected coils.
Preferably, the evaporator may include a plurality of fins having at least 4 fins per 25 millimeters of coil. More preferably, the evaporator includes at least 6 fins per 25 millimeters of coil.
Preferably, the evaporator is cooled using a compressor and condenser system.
Preferably, the condenser may include one or more helically corrugated conduits as described and claimed in PCT/NZ93/00087.
Preferably, the compressor and condenser system includes a compressor, a condenser, and a plurality of capillary tubes, wherein the evaporator includes a plurality of interconnected coils and the capillary tubes feed directly into the evaporator coils, and wherein the compressor provides a gaseous refrigerant under pressure into the condenser, the cooled refrigerant exiting the condenser as a liquid under pressure and being directed to the capillary tubes via a high pressure feed, the capillary tubes then passing the refrigerant in a gaseous form into the evaporator from which the refrigerant exits as a gas under low pressure and returns via a low pressure feed to the compressor, and wherein the system is a closed system.
In one preferred form of apparatus of the present invention the compressor and condenser system may further include a compressor/evaporator line adapted, under pre-determined conditions, to enable hot gas refrigerant from the compressor to enter the coils of the evaporator to melt any ice or frost formed on the evaporator.
Preferably, a solenoid valve may be provided in the secondary line, said valve controllable by the defrost sensor.
Preferably, the plurality of capillary tubes exits from a filter situated between the capillary tubes and the high pressure feed from the condenser.
Preferably, at least one of the capillary tubes enters the evaporator coils at, or adjacent to, the base of the evaporator.
Preferably, the capillary tubes enter the evaporator coils at a variety of positions about the evaporator.
Preferably a TX valve may be used in lieu of the capillary tubes.
Preferably, the gaseous refrigerant exits the evaporator from the top portion of the evaporator.
Preferably, condenser is cooled by air drawn across the condenser by a suction fan situated inside the apparatus or blown across the condenser by a blower situated outside the apparatus.
Preferably, the defrosting means, the air intake device and the temperature of the evaporator are controlled via a single central processing unit.
Preferably, the apparatus includes two water reservoirs, the first being a temporary reservoir being used for temporary storage of water following melting of the ice/frost from the evaporator, the second being a permanent reservoir into which the water from the temporary reservoir is moved for longer term storage, one permanent reservoir can be used.
Preferably, the temporary reservoir contains water level sensors adapted to trigger a pump to move the water contained in the temporary reservoir to the permanent reservoir.
Preferably, the apparatus further includes at least one disinfecting or filtration device adapted to further purify the water. Preferably, the filter is an ozonic filter or an activated charcoal filter. Preferably, the disinfector is an electrical disinfector.
Preferably, the filtration and/or disinfecting device is situated between the temporary reservoir and the permanent reservoir, when one permanent reservoir is used the filtration/disinfecting device may be positioned before the reservoir, or, after the reservoir and before outlet water tap.
In a further preferred form the apparatus of the present invention may further include a heat exchanger connectable to the outlet from the compressor.
Preferably, the heat exchanger may include a conduit within a water tank.
Preferably, said conduit is connectable to the outlet of the compressor via a solenoid valve. Preferably, the solenoid valve may be controlled by the central processing unit.
Preferably, an outlet from the conduit returns to the outlet from the compressor.
Preferably the apparatus further includes an air temperature controller to control the temperature of the air entering the apparatus.
The invention in a second aspect is an apparatus for the production of water from air wherein the apparatus includes:
(a) an air intake device adapted to move air into the apparatus;
(b) an air temperature controller which controls the temperature of the air entering the apparatus;
(c) an evaporator adapted to freeze water contained in the air issuing from the temperature controller; and
(d) a defroster, adapted to defrost the water frozen by the evaporator.
Preferably, the apparatus further includes a reservoir to collect the water created from defrosting the evaporator.
Preferably, the apparatus further comprises an air filter situated to filter the air moving into apparatus.
Preferably, the filter is a washable or a disposable filter.
Preferably, the filter is 200 micron washable filter.
Preferably, the defroster includes a defrost sensor to detect when a predetermined amount of ice or frost has formed in the evaporator.
Preferably, the defroster is a combination of a warming of the evaporator and an increase in the temperature of the air issuing from the temperature controller.
Preferably, the air intake device is a fan adapted to draw air into the apparatus via the air temperature controller and through the evaporator.
Preferably, the air intake device is a blower adapted to force air into the apparatus.
Preferably, the evaporator includes a plurality of interconnected coils.
Preferably, the evaporator includes a plurality of fins having at least 4 fins per 25 millimeters of coil. More preferably, the evaporator includes at least 6 fins per 25 millimeters of coil.
Preferably, the evaporator is cooled using a compressor and condenser system.
Preferably, the air temperature controller includes a first air temperature sensor situated at, or adjacent to, the entrance of the air intake device; and an air heater/cooler positioned between the first air temperature sensor and the evaporator.
Preferably, the air temperature controller includes a second air temperature sensor positioned between the air heater/cooler and the evaporator.
Preferably, the air temperature controller includes a third air temperature sensor positioned such that the evaporator is interposed between the second air temperature sensor and the third air temperature sensor.
Preferably, the heater/cooler in the air temperature controller includes a combination of an air heater and a cold air flow, the cold air flow being directed between the first air temperature sensor and the air heater.
Preferably, the cold airflow is directed from the area adjacent the third air temperature sensor and is channelled to the area between the first air temperature sensor and the air heater via a ducting system which is constrictable in response to cold airflow requirements.
Preferably, the temperature of the airflow from the temperature controller is between about 25xc2x0 C. and about 36xc2x0 C., more preferably between about 29xc2x0 C. and about 32xc2x0 C.
Preferably, the defroster, the air temperature controller, the air intake device and the temperature of the evaporator are controlled via a single central processing unit.
According to a third aspect of the present invention there is provided apparatus for the production of water from air substantially as herein described and with particular reference to FIG. 4.
The invention, in a fourth aspect, may be seen to be a closed loop refrigerant system which includes a compressor, a condenser, an evaporator and a plurality of capillary tubes; wherein the evaporator includes a plurality of interconnecting coils and the capillary tubes feed directly into the evaporator coils and wherein the refrigerant feed from the compressor to the evaporator via the condenser is a high pressure feed, and refrigerant feed from the evaporator to the compressor is a low pressure feed, and wherein the high pressure feed from the condenser to the evaporator includes a single feed exiting the condenser and the plurality of capillary tubes entering the evaporator, the single feed providing the refrigerant to the capillary tubes as a liquid and the capillary tubes providing the refrigerant to the evaporator as a gas.
Preferably, the single feed exiting the condenser enters a refrigerant filter from which the plurality of feeds exit.
Preferably, the plurality of capillary tubes includes between about 3 and about 10 capillary tubes, more preferably about 5 capillary tubes.
Preferably, at least one of the capillary tubes provides gaseous refrigerant into the evaporator tubes at, or adjacent to, the base of the evaporator.
Preferably, the capillary tubes enter the evaporator coils at variety of positions in the evaporator.
Preferably, the gaseous refrigerant exits the evaporator tubes in the evaporator from the top portion of the evaporator.
Preferably a TX valve may be used in lieu of the capillary tubes.
Preferably, the condenser is cooled by air drawn across the condenser by a suction fan situated inside the apparatus or blown across the condenser by a blower situated outside the apparatus.
Other aspects of the present invention may become apparent from the following description which is given by way of example only and with reference to the accompanying drawings.